[b]Simple Circular Fillet Demo[/b] — fillets are used in engineering to replace sharp corners with rounded edges. This is usually done to increase the strength of the part, as sharp corners can act like cracks. This is a very rudimentary demo, as you get surprising results if the points G and I are too close, and perplexing ones if the angle goes past 180°. It is doing [i]exactly[/i] what it's supposed to do, though; that's why writing code to define fillets the way users expect is much harder than you'd think!